本研究將石墨烯 (graphene)與聚二甲基二烯丙基氯化銨 (PDDA)合成出表面帶正電之graphene-PDDA，再加入以檸檬酸鈉熱還原法製備表面帶負電之金奈米粒子 (gold nanoparticles，Au NPs)，經由兩者之間的靜電作用力使得金奈米粒子能吸附於表面並且有良好的分散性，而製備出金奈米粒子/石墨烯 (Au/Graphene-PDDA)複合物，Au/Graphene-PDDA具有光學穿透性並且能夠提升對於微生物的接觸面積進而提高表面增強拉曼光譜 (surface-enhanced Raman scattering，SERS)偵測的靈敏度，可用於偵測小分子腺嘌呤 (adenine)、微生物金黃色葡萄球菌 (S. aureus)之SERS訊號，最後藉由改變金奈米粒子與石墨烯之間的比例，可控制金奈米粒子於Graphene-PDDA表面形態及粒子間距，藉此尋找最佳SERS增強效應之金奈米粒子與石墨烯的比例，以應用於生物檢測。

In this research, graphene nanosheets was functionalized with cationic poly(diallyldimethyl ammonium chloride) (PDDA). Simultaneously, the citrate-capped gold nanoparticles (AuNPs) were synthesized through the traditional citrate thermal reduction method. Then the resulting AuNPs were adsorbed to Graphene-PDDA through electrostatic interaction. These nanohybrids of Au/Graphene-PDDA exhibited good dispersion and optical transparency, which increased the surface-area between the substrate and microorganisms, thus enhancing surface-enhanced Raman scattering (SERS) sensitivity. Au/Graphene-PDDA substrate can be widely used in SERS detection of small molecules (adenine) and microorganisms (S. aureus). Finally, the morphology and particle spacing of Au/Graphene-PDDA can be controlled by varying the ratio of the proportion between AuNPs and graphene-PDDA, thereby optimizing the SERS enhancement effect. Thus these nanohybrids can be used for biosensing.

[1] D. A. Long, "Introductory Raman Spectroscopy. John R. Ferraro, Kazuo Nakamoto and Chris W. Brown. Academic Press, Amsterdam, Second Edition, 2003. xiii + 434," Journal of Raman Spectroscopy, vol. 36, pp. 1012-1012, 2005.
[2] M. Fleischmann, P. J. Hendra, and A. J. McQuillan, "Raman spectra of pyridine adsorbed at a silver electrode," Chemical Physics Letters, vol. 26, pp. 163-166, 5/15/ 1974.
[3] W. E. Doering and S. Nie, "Single-Molecule and Single-Nanoparticle SERS:  Examining the Roles of Surface Active Sites and Chemical Enhancement," The Journal of Physical Chemistry B, vol. 106, pp. 311-317, 2002/01/01 2001.
[4] N. Félidj, J. Aubard, G. Lévi, J. R. Krenn, A. Hohenau, G. Schider, et al., "Optimized surface-enhanced Raman scattering on gold nanoparticle arrays," Applied Physics Letters, vol. 82, pp. 3095-3097, 2003.
[5] S. Nie and S. R. Emory, "Probing Single Molecules and Single Nanoparticles by Surface-Enhanced Raman Scattering," Science, vol. 275, pp. 1102-1106, February 21, 1997 1997.
[6] K. Kneipp, Y. Wang, H. Kneipp, L. T. Perelman, I. Itzkan, R. R. Dasari, et al., "Single Molecule Detection Using Surface-Enhanced Raman Scattering (SERS)," Physical Review Letters, vol. 78, pp. 1667-1670, 03/03/ 1997.
[7] A. Campion and P. Kambhampati, "Surface-enhanced Raman scattering," Chemical Society Reviews, vol. 27, pp. 241-250, 1998.
[8] D. L. Jeanmaire and R. P. Van Duyne, "Surface raman spectroelectrochemistry: Part I. Heterocyclic, aromatic, and aliphatic amines adsorbed on the anodized silver electrode," Journal of Electroanalytical Chemistry and Interfacial Electrochemistry, vol. 84, pp. 1-20, 11/10/ 1977.
[9] M. G. Albrecht and J. A. Creighton, "Anomalously intense Raman spectra of pyridine at a silver electrode," Journal of the American Chemical Society, vol. 99, pp. 5215-5217, 1977/06/01 1977.
[10] E. C. Le Ru, E. Blackie, M. Meyer, and P. G. Etchegoin, "Surface Enhanced Raman Scattering Enhancement Factors:  A Comprehensive Study," The Journal of Physical Chemistry C, vol. 111, pp. 13794-13803, 2007/09/01 2007.
[11] A. J. Haes and R. P. Van Duyne, "A unified view of propagating and localized surface plasmon resonance biosensors," Analytical and Bioanalytical Chemistry, vol. 379, pp. 920-930, Aug 2004.
[12] K. L. Kelly, E. Coronado, L. L. Zhao, and G. C. Schatz, "The Optical Properties of Metal Nanoparticles:  The Influence of Size, Shape, and Dielectric Environment," The Journal of Physical Chemistry B, vol. 107, pp. 668-677, 2003/01/01 2002.
[13] E. C. Le Ru and P. G. Etchegoin, "Chapter 3 - Introduction to plasmons and plasmonics," in Principles of Surface-Enhanced Raman Spectroscopy, E. C. L. Ru and P. G. Etchegoin, Eds., ed Amsterdam: Elsevier, 2009, pp. 121-183.
[14] H. Xu, E. J. Bjerneld, M. Käll, and L. Börjesson, "Spectroscopy of Single Hemoglobin Molecules by Surface Enhanced Raman Scattering," Physical Review Letters, vol. 83, pp. 4357-4360, 11/22/ 1999.
[15] E. Hao and G. C. Schatz, "Electromagnetic fields around silver nanoparticles and dimers," The Journal of Chemical Physics, vol. 120, pp. 357-366, 2004.
[16] T. R. Jensen, G. C. Schatz, and R. P. Van Duyne, "Nanosphere Lithography:  Surface Plasmon Resonance Spectrum of a Periodic Array of Silver Nanoparticles by Ultraviolet−Visible Extinction Spectroscopy and Electrodynamic Modeling," The Journal of Physical Chemistry B, vol. 103, pp. 2394-2401, 1999/04/01 1999.
[17] G. L. Liu and L. P. Lee, "Nanowell surface enhanced Raman scattering arrays fabricated by soft-lithography for label-free biomolecular detections in integrated microfluidics," Applied Physics Letters, vol. 87, pp. -, 2005.
[18] H. H. Wang, C. Y. Liu, S. B. Wu, N. W. Liu, C. Y. Peng, T. H. Chan, et al., "Highly Raman-enhancing substrates based on silver nanoparticle arrays with tunable sub-10 nm gaps," Advanced Materials, vol. 18, pp. 491-+, Feb 2006.
[19] P. Kao, N. A. Malvadkar, M. Cetinkaya, H. Wang, D. L. Allara, and M. C. Demirel, "Surface-Enhanced Raman Detection on Metalized Nanostructured Poly(p-xylylene) Films," Advanced Materials, vol. 20, pp. 3562-3565, 2008.
[20] D. A. Handley, "Colloidal Gold : Principles,Methods, and Applications," Academic Press, vol. 1, 1989.
[21] M. Faraday, "The Bakerian Lecture: Experimental Relations of Gold (and Other Metals) to Light," Philosophical Transactions of the Royal Society of London, vol. 147, pp. 145-181, 1857.
[22] K. Kneipp, A. S. Haka, H. Kneipp, K. Badizadegan, N. Yoshizawa, C. Boone, et al., "Surface-enhanced Raman Spectroscopy in single living cells using gold nanoparticles," Applied Spectroscopy, vol. 56, pp. 150-154, Feb 2002.
[23] C. E. Talley, J. B. Jackson, C. Oubre, N. K. Grady, C. W. Hollars, S. M. Lane, et al., "Surface-enhanced Raman scattering from individual Au nanoparticles and nanoparticle dimer substrates," Nano Letters, vol. 5, pp. 1569-1574, Aug 2005.
[24] C. J. Orendorff, A. Gole, T. K. Sau, and C. J. Murphy, "Surface-Enhanced Raman Spectroscopy of Self-Assembled Monolayers:  Sandwich Architecture and Nanoparticle Shape Dependence," Analytical Chemistry, vol. 77, pp. 3261-3266, 2005/05/01 2005.
[25] J. Kimling, M. Maier, B. Okenve, V. Kotaidis, H. Ballot, and A. Plech, "Turkevich Method for Gold Nanoparticle Synthesis Revisited," The Journal of Physical Chemistry B, vol. 110, pp. 15700-15707, 2006/08/01 2006.
[26] J. Turkevich, P. C. Stevenson, and J. Hillier, "A study of the nucleation and growth processes in the synthesis of colloidal gold," Discussions of the Faraday Society, vol. 11, pp. 55-75, 1951.
[27] H. B. Weiser, "Inorganic Colloid Chemistry," Wiley, New York, NY, vol. 1, pp. 21-57, 1933.
[28] S. Kumar, K. S. Gandhi, and R. Kumar, "Modeling of Formation of Gold Nanoparticles by Citrate Method＋," Industrial & Engineering Chemistry Research, vol. 46, pp. 3128-3136, 2007/05/01 2006.
[29] A. K. G. a. P. Kim, "Graphene, a newly isolated form of carbon, provides a rich lode of novel fundamental physics and practical applications," Scientific American, vol. 298, pp. 90-97, 2008.
[30] G. Eda, G. Fanchini, and M. Chhowalla, "Large-area ultrathin films of reduced graphene oxide as a transparent and flexible electronic material," Nat Nano, vol. 3, pp. 270-274, 05//print 2008.
[31] A. K. Geim and K. S. Novoselov, "The rise of graphene," Nat Mater, vol. 6, pp. 183-191, 03//print 2007.
[32] K. S. Novoselov, A. K. Geim, S. V. Morozov, D. Jiang, Y. Zhang, S. V. Dubonos, et al., "Electric Field Effect in Atomically Thin Carbon Films," Science, vol. 306, pp. 666-669, October 22, 2004 2004.
[33] J. Meyer, A. Chuvilin, and U. Kaiser, "Electron Microscopic Studies with Graphene," Microscopy and Microanalysis, vol. 15, pp. 126-127, 2009.
[34] C. Andrey, C. M. Jannik, A.-S. Gerardo, and K. Ute, "From graphene constrictions to single carbon chains," New Journal of Physics, vol. 11, p. 083019, 2009.
[35] C. Lee, X. Wei, J. W. Kysar, and J. Hone, "Measurement of the Elastic Properties and Intrinsic Strength of Monolayer Graphene," Science, vol. 321, pp. 385-388, July 18, 2008 2008.
[36] A. A. Balandin, S. Ghosh, W. Bao, I. Calizo, D. Teweldebrhan, F. Miao, et al., "Superior Thermal Conductivity of Single-Layer Graphene," Nano Letters, vol. 8, pp. 902-907, 2008/03/01 2008.
[37] K. I. Bolotin, K. J. Sikes, Z. Jiang, M. Klima, G. Fudenberg, J. Hone, et al., "Ultrahigh electron mobility in suspended graphene," Solid State Communications, vol. 146, pp. 351-355, 6// 2008.
[38] J. Rafiee, X. Mi, H. Gullapalli, A. V. Thomas, F. Yavari, Y. Shi, et al., "Wetting transparency of graphene," Nat Mater, vol. 11, pp. 217-222, 03//print 2012.
[39] S. Chen, Q. Wu, C. Mishra, J. Kang, H. Zhang, K. Cho, et al., "Thermal conductivity of isotopically modified graphene," Nat Mater, vol. 11, pp. 203-207, 03//print 2012.
[40] A. H. C. Neto and K. Novoselov, "New directions in science and technology: two-dimensional crystals," Reports on Progress in Physics, vol. 74, p. 082501, 2011.
[41] K. S. Novoselov, A. K. Geim, S. V. Morozov, D. Jiang, M. I. Katsnelson, I. V. Grigorieva, et al., "Two-dimensional gas of massless Dirac fermions in graphene," Nature, vol. 438, pp. 197-200, 11/10/print 2005.
[42] K. S. Novoselov and A. H. C. Neto, "Two-dimensional crystals-based heterostructures: materials with tailored properties," Physica Scripta, vol. 2012, p. 014006, 2012.
[43] Y. Iyechika, "Application of graphene to high-speed transistors: expectations and challenges," Science and Technology Trends - Quarterly Review, vol. 37, pp. 76-92, 2010.
[44] A. Reina, X. T. Jia, J. Ho, D. Nezich, H. B. Son, V. Bulovic, et al., "Large Area, Few-Layer Graphene Films on Arbitrary Substrates by Chemical Vapor Deposition," Nano Letters, vol. 9, pp. 30-35, Jan 2009.
[45] A. N. Obraztsov, E. A. Obraztsova, A. V. Tyurnina, and A. A. Zolotukhin, "Chemical vapor deposition of thin graphite films of nanometer thickness," Carbon, vol. 45, pp. 2017-2021, Sep 2007.
[46] I. Vlassiouk, M. Regmi, P. Fulvio, S. Dai, P. Datskos, G. Eres, et al., "Role of Hydrogen in Chemical Vapor Deposition Growth of Large Single-Crystal Graphene," ACS Nano, vol. 5, pp. 6069-6076, 2011/07/26 2011.
[47] K. C. Yung, W. M. Wu, M. P. Pierpoint, and F. V. Kusmartsev, "Introduction to graphene electronics – a new era of digital transistors and devices," Contemporary Physics, vol. 54, pp. 233-251, 2013/09/01 2013.
[48] H. He, J. Klinowski, M. Forster, and A. Lerf, "A new structural model for graphite oxide," Chemical Physics Letters, vol. 287, pp. 53-56, 4/24/ 1998.
[49] A. Lerf, H. Y. He, M. Forster, and J. Klinowski, "Structure of graphite oxide revisited," Journal of Physical Chemistry B, vol. 102, pp. 4477-4482, Jun 4 1998.
[50] M. Hirata, T. Gotou, S. Horiuchi, M. Fujiwara, and M. Ohba, "Thin-film particles of graphite oxide 1: High-yield synthesis and flexibility of the particles," Carbon, vol. 42, pp. 2929-2937, 2004.
[51] T. Szabo, A. Szeri, and I. Dekany, "Composite graphitic nanolayers prepared by self-assembly between finely dispersed graphite oxide and a cationic polymer," Carbon, vol. 43, pp. 87-94, 2005.
[52] B. C. Brodie, "Sur le poids atomique du graphite," Ann. Chim. Phys., vol. 59, pp. 466-472, 1860.
[53] L. Staudenmaier, "Verfahren zur Darstellung der Graphitsäure," Berichte der deutschen chemischen Gesellschaft, vol. 31, pp. 1481-1487, 1898.
[54] W. S. Hummers and R. E. Offeman, "Preparation of Graphitic Oxide," Journal of the American Chemical Society, vol. 80, pp. 1339-1339, 1958/03/01 1958.
[55] A. Bagri, C. Mattevi, M. Acik, Y. J. Chabal, M. Chhowalla, and V. B. Shenoy, "Structural evolution during the reduction of chemically derived graphene oxide," Nat Chem, vol. 2, pp. 581-587, 07//print 2010.
[56] G. B. Butler and R. J. Angelo, "Preparation and Polymerization of Unsaturated Quaternary Ammonium Compounds. VIII. A Proposed Alternating Intramolecular-Intermolecular Chain Propagation1," Journal of the American Chemical Society, vol. 79, pp. 3128-3131, 1957/06/01 1957.
[57] J. Lu, X. D. Wang, and C. B. Xiao, "Preparation and characterization of konjac glucomannan/poly(diallydimethylammonium chloride) antibacterial blend films," Carbohydrate Polymers, vol. 73, pp. 427-437, Aug 2008.
[58] C. Wandrey, J. Hernández-Barajas, and D. Hunkeler, "Diallyldimethylammonium Chloride and its Polymers," in Radical Polymerisation Polyelectrolytes. vol. 145, I. Capek, J. Hernfández-Barajas, D. Hunkeler, J. L. Reddinger, J. R. Reynolds, and C. Wandrey, Eds., ed: Springer Berlin Heidelberg, 1999, pp. 123-183.
[59] B. P. Tripathi, N. C. Dubey, and M. Stamm, "Functional polyelectrolyte multilayer membranes for water purification applications," Journal of Hazardous Materials, vol. 252, pp. 401-412, May 2013.
[60] D. Q. Yang, J. F. Rochette, and E. Sacher, "Spectroscopic evidence for pi-pi interaction between poly(diallyl dimethylammonium) chloride and multiwalled carbon nanotubes," Journal of Physical Chemistry B, vol. 109, pp. 4481-4484, Mar 17 2005.
[61] S. Link and M. A. El-Sayed, "Spectral Properties and Relaxation Dynamics of Surface Plasmon Electronic Oscillations in Gold and Silver Nanodots and Nanorods," The Journal of Physical Chemistry B, vol. 103, pp. 8410-8426, 1999/10/01 1999.